For exact camera positioning for close-up, macrophotography and copying. Two positioning scales are perpendicular to one another. Setting range each 95 mm (3.7 in.). Prismatic precision guideways with micro adjustment across helical gear rack-and-pinion assemblies complete with lock screws and dials calibrated in millimeters. Mounting plate with rubber pad. 1/4" camera mounting screw 1/4" connecting thread